target/linux/coldfire/files-2.6.31/arch/m68k/coldfire/common/time.c

   1 /*
   2  *  linux/arch/m68k/coldfire/time.c
   3  *
   4  *  This file contains the coldfire specific time handling pieces.
   5  *
   6  *  Copyright 2008-2009 Freescale Semiconductor, Inc. All Rights Reserved.
   7  *  Kurt Mahan <kmahan@freescale.com>
   8  *  Jason Jin Jason.Jin@freescale.com
   9  *  Shrek Wu B16972@freescale.com
  10  *
  11  *  based on linux/arch/m68k/kernel/time.c
  12  */
  13 #include <linux/clk.h>
  14 #include <linux/clk.h>
  15 #include <linux/clocksource.h>
  16 #include <linux/clockchips.h>
  17 #include <linux/time.h>
  18 #include <linux/timex.h>
  19 #include <linux/errno.h>
  20 #include <linux/module.h>
  21 #include <linux/sysdev.h>
  22 #include <linux/sched.h>
  23 #include <linux/kernel.h>
  24 #include <linux/param.h>
  25 #include <linux/string.h>
  26 #include <linux/mm.h>
  27 #include <linux/rtc.h>
  28
  29 #include <asm/machdep.h>
  30 #include <linux/io.h>
  31 #include <asm/irq_regs.h>
  32
  33 #include <linux/profile.h>
  34 #include <asm/mcfsim.h>
  35 #ifdef CONFIG_GENERIC_CLOCKEVENTS
  36 /*extern unsigned long long sys_dtim0_read(void);
  37 extern void sys_dtim_init(void);*/
  38 extern unsigned long long sys_dtim2_read(void);
  39 extern void sys_dtim2_init(void);
  40 static int cfv4_set_next_event(unsigned long evt,
  41         struct clock_event_device *dev);
  42 static void cfv4_set_mode(enum clock_event_mode mode,
  43         struct clock_event_device *dev);
  44 #if defined(CONFIG_M5445X)
  45 #define FREQ    (MCF_BUSCLK / 16)
  46 #else
  47 #define FREQ    (MCF_BUSCLK)
  48 #endif
  49 /*
  50  * realtime clock dummy code
  51  */
  52
  53 static unsigned long null_rtc_get_time(void)
  54 {
  55         return mktime(2008, 1, 1, 0, 0, 0);
  56 }
  57
  58 static int null_rtc_set_time(unsigned long sec)
  59 {
  60         return 0;
  61 }
  62
  63 static unsigned long (*cf_rtc_get_time)(void) = null_rtc_get_time;
  64 static int (*cf_rtc_set_time)(unsigned long) = null_rtc_set_time;
  65 #endif /* CONFIG_GENERIC_CLOCKEVENTS */
  66
  67 /*
  68  * old pre-GENERIC clock code
  69  */
  70
  71 #ifndef CONFIG_GENERIC_CLOCKEVENTS
  72 /*
  73  * timer_interrupt() needs to keep up the real-time clock,
  74  * as well as call the "do_timer()" routine every clocktick
  75  */
  76 static irqreturn_t timer_interrupt(int irq, void *dummy)
  77 {
  78 #ifdef CONFIG_COLDFIRE
  79         /* kick hardware timer if necessary */
  80         if (mach_tick)
  81                 mach_tick();
  82 #endif
  83         do_timer(1);
  84 #ifndef CONFIG_SMP
  85         update_process_times(user_mode(get_irq_regs()));
  86 #endif
  87         profile_tick(CPU_PROFILING);
  88
  89 #ifdef CONFIG_HEARTBEAT
  90         /* use power LED as a heartbeat instead -- much more useful
  91            for debugging -- based on the version for PReP by Cort */
  92         /* acts like an actual heart beat -- ie thump-thump-pause... */
  93         if (mach_heartbeat) {
  94                 unsigned cnt = 0, period = 0, dist = 0;
  95
  96                 if (cnt == 0 || cnt == dist)
  97                         mach_heartbeat(1);
  98                 else if (cnt == 7 || cnt == dist+7)
  99                         mach_heartbeat(0);
 100
 101                 if (++cnt > period) {
 102                         cnt = 0;
 103                         /* The hyperbolic function below modifies
 104                          * the heartbeat period length in dependency
 105                          * of the current (5min) load. It goes through
 106                          * the points f(0)=126, f(1)=86, f(5)=51,
 107                          * f(inf)->30. */
 108                         period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT)))
 109                                         + 30;
 110                         dist = period / 4;
 111                 }
 112         }
 113 #endif /* CONFIG_HEARTBEAT */
 114         return IRQ_HANDLED;
 115 }
 116
 117 void __init time_init(void)
 118 {
 119         struct rtc_time time;
 120
 121         if (mach_hwclk) {
 122                 mach_hwclk(0, &time);
 123                 time.tm_year += 1900;
 124                 if (time.tm_year < 1970)
 125                         time.tm_year += 100;
 126                 xtime.tv_sec = mktime(time.tm_year, time.tm_mon, time.tm_mday,
 127                                       time.tm_hour, time.tm_min, time.tm_sec);
 128                 xtime.tv_nsec = 0;
 129         }
 130         wall_to_monotonic.tv_sec = -xtime.tv_sec;
 131
 132         mach_sched_init(timer_interrupt);
 133 }
 134 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */
 135
 136 #ifndef CONFIG_GENERIC_TIME
 137 /*
 138  * This version of gettimeofday has near microsecond resolution.
 139  */
 140 void do_gettimeofday(struct timeval *tv)
 141 {
 142         unsigned long flags;
 143         unsigned long seq;
 144         unsigned long usec, sec;
 145         unsigned long max_ntp_tick = tick_usec - tickadj;
 146
 147         do {
 148                 seq = read_seqbegin_irqsave(&xtime_lock, flags);
 149
 150                 usec = mach_gettimeoffset();
 151
 152                 /*
 153                  * If time_adjust is negative then NTP is slowing the clock
 154                  * so make sure not to go into next possible interval.
 155                  * Better to lose some accuracy than have time go backwards..
 156                  */
 157                 if (unlikely(time_adjust < 0))
 158                         usec = min(usec, max_ntp_tick);
 159
 160                 sec = xtime.tv_sec;
 161                 usec += xtime.tv_nsec/1000;
 162         } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
 163
 164
 165         while (usec >= 1000000) {
 166                 usec -= 1000000;
 167                 sec++;
 168         }
 169
 170         tv->tv_sec = sec;
 171         tv->tv_usec = usec;
 172 }
 173 EXPORT_SYMBOL(do_gettimeofday);
 174
 175 int do_settimeofday(struct timespec *tv)
 176 {
 177         time_t wtm_sec, sec = tv->tv_sec;
 178         long wtm_nsec, nsec = tv->tv_nsec;
 179
 180         if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 181                 return -EINVAL;
 182
 183         write_seqlock_irq(&xtime_lock);
 184         /* This is revolting. We need to set the xtime.tv_nsec
 185          * correctly. However, the value in this location is
 186          * is value at the last tick.
 187          * Discover what correction gettimeofday
 188          * would have done, and then undo it!
 189          */
 190         nsec -= 1000 * mach_gettimeoffset();
 191
 192         wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
 193         wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
 194
 195         set_normalized_timespec(&xtime, sec, nsec);
 196         set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 197
 198         ntp_clear();
 199         write_sequnlock_irq(&xtime_lock);
 200         clock_was_set();
 201         return 0;
 202 }
 203 EXPORT_SYMBOL(do_settimeofday);
 204 #endif /* !CONFIG_GENERIC_TIME */
 205
 206 #ifdef CONFIG_GENERIC_CLOCKEVENTS
 207 /*
 208  * Clock Evnt setup
 209  */
 210 static struct clock_event_device clockevent_cfv4 = {
 211         .name           = "CFV4 timer2even",
 212         .features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
 213         .rating         = 200,
 214         .shift          = 20,
 215         .set_mode       = cfv4_set_mode,
 216         .set_next_event = cfv4_set_next_event,
 217 };
 218
 219 static int cfv4_set_next_event(unsigned long evt,
 220         struct clock_event_device *dev)
 221 {
 222         return 0;
 223 }
 224
 225 static void cfv4_set_mode(enum clock_event_mode mode,
 226         struct clock_event_device *dev)
 227 {
 228         if (mode != CLOCK_EVT_MODE_ONESHOT)
 229                 cfv4_set_next_event((FREQ / HZ), dev);
 230 }
 231
 232 static int __init cfv4_clockevent_init(void)
 233 {
 234         clockevent_cfv4.mult =
 235                         div_sc(FREQ, NSEC_PER_SEC,
 236                         clockevent_cfv4.shift);
 237         clockevent_cfv4.max_delta_ns =
 238                 clockevent_delta2ns((FREQ / HZ),
 239                         &clockevent_cfv4);
 240         clockevent_cfv4.min_delta_ns =
 241                 clockevent_delta2ns(1, &clockevent_cfv4);
 242
 243         clockevent_cfv4.cpumask = &cpumask_of_cpu(0);
 244
 245         printk(KERN_INFO "timer: register clockevent\n");
 246                 clockevents_register_device(&clockevent_cfv4);
 247
 248         return 0;
 249 }
 250
 251 /*
 252  * clocksource setup
 253  */
 254
 255 struct clocksource clocksource_cfv4 = {
 256         .name   = "ColdfireV4",
 257         .rating = 250,
 258         .mask   = CLOCKSOURCE_MASK(32),
 259         .read   = sys_dtim2_read,
 260         .shift  = 20,
 261         .flags  = CLOCK_SOURCE_IS_CONTINUOUS,
 262 };
 263
 264 /*
 265  * Initialize time subsystem.  Called from linux/init/main.c
 266  */
 267 void __init time_init(void)
 268 {
 269         int ret;
 270
 271         printk(KERN_INFO "Initializing time\n");
 272 #if 0
 273         /* initialize system clocks */
 274         clk_init();
 275 #endif
 276         cfv4_clockevent_init();
 277         /* initialize the system timer */
 278         /*sys_dtim_init();*/
 279         sys_dtim2_init();
 280         /* setup initial system time */
 281         xtime.tv_sec = cf_rtc_get_time();
 282         xtime.tv_nsec = 0;
 283         set_normalized_timespec(&wall_to_monotonic, -xtime.tv_sec,
 284                                 -xtime.tv_nsec);
 285
 286         /* JKM */
 287         clocksource_cfv4.mult = clocksource_hz2mult(FREQ,
 288                         clocksource_cfv4.shift);
 289
 290         /* register our clocksource */
 291         ret = clocksource_register(&clocksource_cfv4);
 292         if (ret)
 293                 printk(KERN_ERR "timer: unable to "
 294                         "register clocksource - %d\n", ret);
 295 }
 296
 297 /*
 298  * sysfs pieces
 299  */
 300
 301 static struct sysdev_class timer_class = {
 302         .name   = "timer",
 303 };
 304
 305 static struct sys_device timer_device = {
 306         .id     = 0,
 307         .cls    = &timer_class,
 308 };
 309
 310 static int __init timer_init_sysfs(void)
 311 {
 312         int err = sysdev_class_register(&timer_class);
 313         if (!err)
 314                 err = sysdev_register(&timer_device);
 315         return err;
 316 }
 317 device_initcall(timer_init_sysfs);
 318 #endif /* CONFIG_GENERIC_CLOCKEVENTS */